Continuous-current transformer



(No Model.) I 3 SheetsSheet 1.

E. THOMSON.

CONTINUOUS CURRENT TRANSFORMER. 7

No. 486,669. Patented Nov. 8, 1892.

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(No Model.) 3 Sheets-Sheet 2.

E. THOMSON.

CONTINUOUS CURRENT TRANSFORMER.

Patented Nov. 8, 1892.

WITNEESEEI- 2/5 umo, wnsummou o c (No Model.) 3 Sheets-Sheet 3.

" E. THOMSON.

CONTINUOUS CURRENT TRANSFORMER.

No. 485,669. Patented NOV. 8, 1892.

UNITED: STATns ATENT union.

ELIHU TI-IOMSON,'OF SVVAMPSCOT", MASSACHUSETTS, ASSIGNOR TO THETHOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

CONTINUOUS-CURRENT TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 485,669, dated November8, 1892.

Application filed August 28.1891. Serial No. (N0 11105819 To all whom itmay concern:

Be it known that I, ELIHU THOMSON, a citizen of the United States,residing at Swampscott, in the county of Essex and State ofMassachusetts, have invented a certain new and useful Improvement inContinuous-Current Transformers, of which the following is aspecification.

The present invention relates to improvements in continuous-currenttransformers. Some of the improvements are useful, generally, in theconstruction of such machines. Others are for the purpose of adaptingsuch transformers to special uses, such as the obtaining of secondarycurrents of slow rates of pulsation such as are adapted to be used inthe operation of reciprocating drills and other reciprocating tools.

In the accompanying drawings, Figure 1 is an axial section of acontinuous-currenttransformer. Fig. 2 is a transverse section, and Fig.3 an end elevation, of the same. Figs. 4 and 5 show details.

In Fig. 1, B B is a base-plate having mounted upon it standards J J,from each of which an arm :1: projects for sustaining a central shaft Xin a fixed position or without revolution. These standards J J alsosupport journals or boxes 8 for a hollow shaft or hollow sleeves S S,which carry the revoluble portion of the apparatus. These hollow sleevessurround the shaft X, but clear the same by a small space. On the shaftX X and between the sleeves S S is fixed and sustained an iron body M,preferably constructed of laminated iron and which forms a source offield energy in the 1nach'ine,or, in other words, is the field-magnet.This field-magnet has its coil wound in diametrically-opposite notches,as in the old Siemens H-armature. This magnetic body M is surrounded bythe armature N of the machine, which is also a laminated body of iron inthe form of a ring or constructed of sections of rings of sheet-iron.These laminations or rings are bolted together in the ordinary Way tokeep them in place and form a massive laminated ring. The armature-bodyN is preferably provided with long projections n n n n, &c., extendingradially toward the inner field-core M and clearing it by a very smallspace. By this means the magnetic circuit of the field-magnet M is verythoroughly and completely closed without the necessity for anyconsiderable air-gap. In this respect myinvention difiers from theordinary dynamo-machines, which do not operate properly unless theair-gap is made considerable, experience having shown that it isnecessary to have acertain air resistance between the field and thearmature core it the armature is to carry any considerable load ofcurrent. This is owing to the distortive effects of thearmature-currents on the field, or owing, more accurately, to acrossinductive action, which breaks down the magnetic field in which thearmature exists. This cross-inductive action is relieved by allowing alarge clearance. In my invention only that amount of clearance which isrequisite for mechanical reasons is needed. Hence Ioperate in mytransformer with practically a closed magnetic circuit, thereby savingenergy which would be required to be put into the field-coil C C savingthe metal, which would otherwise be required in the field-magnet M M,and saving considerably in the wire, which would be required tomagnetize the same, at the same time that I can bring the iron to a highdegree of magnetization. The present invention relating tocontinuouscurrent transformers, the armature-core N is wound with twosets of coils, preferably superposed in the spaces provided and passingoutwardly over the exterior and separated. These coils are connectedinto a closed series, as in the Grainme winding, each forming a'separateclosed series while insulated one from the other and from the core N N.The coils do not require any binding to keep them in place interiorly,because of the fact that the centrifugal force tends to keep thembetween the projections a it n n. The structure so wound with coils, thegage of wire of which may be selected in accordance with the relativepotentials of the windings, is mounted in a framework consisting ofexterior metal pieces A A A, &c.-, set into notches on the exteriorsurface of the laminated structure N N,

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as indicated in Fig. They may be made to project out laterally, as inFig. 1, and be formed with a thread and shoulder, allowing them to enterinto corresponding holes in end plates or spiders G G, provided fortheir reception. These plates or spiders G G are centered upon thesleeves S S, to which they are firmly secured, as shown in Fig. l. Thearmature is thus carried during revolution by the parts A A, mounted onthe plates or spiders G G, which, with the sleeves S S, revolve in thebearings in the upper parts of the standards J J and around thestationary field M M. A commutator K, provided with brushes bearingthereon in the usual manner, is mounted upon the sleeve S and has itssegments connected, respectively, to the coils of one of the windings onthe armature-body N N, while another commutator K has its segmentssimilarly connected to the other winding. The commutator K may be thatbelongingto the high-potential winding, receiving, say, five hundred,one thousand, or more volts of current and transforming it anddelivering it at a lower potential to the commutator K, upon which restsin suitable position a set of brushes for taking up the cur rent anddelivering it to the secondary circuit. The field-magnet coil 0 C isenergized 0 by wires carried through a holemin the shaft X from one end,and this current may be taken from anysuitable source. On the completionof the circuit through the windings and the excitation of the held thearmature 5 revolves at a speed dependent upon the counter electro-motiveforce developed in its turns in relation to the applied electro-motiveforce. Referring now to Fig. 3, G represents the supporting-spider, andthe coils of the arma- 4o ture-bodyNN are seen in place with the supporting-frame or metallic bars A A sustained in the spider G. Thesegments of the commutator K are also partly visible in that figure. Thebrushes resting on the commutator 5 K K are seen in Fig. 3 at E E andare shown as carbon brushes mounted in holders sustained in the frame orring Rand insulated therefrom. This frame or ring R (see Fig. 1) isshown supported from the journalbox 3 s, and from this support extendsupward an arm a, carrying a collector-brush b,

as seen, also, in Fig. 3. This brush 2) is attached to a support and awire connection carried therefrom wherever desired. It rests byspring-pressure upon a circular ring or frame H, Figs. 1 and 3, whichframe H carries another brush F, resting on the commutator K andelectrically connected with the frame H. The ring R sustains a set ofthree grooved rolls V, preferably of insulated material, which areconstructed with a V-groove bearing on the inner double-cone surface ofthe ring H and sustaining it. They also bear on adouble-cone surfacecarried on the sleeve S. Hence when the sleeve S revolves motion iscommunicated to the rolls and thereby to the ring H; bu'tits rate ofrotation is slower and opposite to that of the sleeve S. This results incarrying the brush F around the comm utatorduringthe action of themachine, and since the brushes on the commutator K, as well as those onthe commutatorK-namely, EEare stationary the revolution of the brush Fwill deliver to the brush 1) alternating potentials at rates dependentupon the rate of its revolution over the commutatorsurface, and if theconnectionbemade through a circuit. from the brush 1) to either of thebrushesEE' the effect will be to send through such circuit pulsatingcurrents at a speed de pendent upon the speed of revolution of thebrush. If two brushesF were mounted on the ring II II and similarlyrevolved, it is evident that if they are kept insulated and separatemeans-such as two outer surfaces and two separate brushes, as bwereprovided, alternating impulses or alternating currents of slow periodmight be taken in like manner to the pulsating ci'irrents between thetwo brushes mounted like F and their connections exterior-1y. This isrendered more plain by reference to Fig. 5, where the brushes F F,bearing on opposite parts of the commutator K, are mounted on the frameH and connected, respectively, to two insulated rings h h, from whichbrushes 1) I) lead to the two sides of the secondary circuit.

Fig. 4. simply shows the winding of coarse and fine wire in coils, whichare to be laid upon the armature and between the projections at n of thearmature-body N. On account of the fact that the armature-currents inthe two windings are proportionate to each other and that they arecounter-distortive, so far as the field is concerned or tendency toshift the magnetism in opposite directions, the machine becomes freefrom distortion, the brushes may be placed onthe middle linebctween thefield-poles or the wire connections from the commutator to the coils maybe twisted to place them in any favorable position, and they will notrequire to be afterward adjusted during changes of load. At the sametime the full el'lect of the comparatively-small fieldmagnet M isobtainable, working over a substantially-closed magnetic circuit withoutdistortion or cross-induction. I am thus enabled to provide space foralarge amount of armature-wire, to provide ample section for carryingheavy currents therein, and at the same time to magnetize the armatureto the fullest extent by a very moderate expenditure of energy in thefield-magnet coil. My construction also gives a verythoroughlyventilated armature, or one which during revolution gives afree exposure of the coils to the air on its exterior. The machine isalso adaptable, as is evident, to trans forming for difference ofpotential between the two windings and to deliver pulsating oralternating currents of slow period from the secondary winding whiletaking comparatively-high potentials in the primary winding. The devicesfor rotating the brushes on the commutator K are simple and efficient.

It is apparent that some of the features of construction hereinbeforeset forth are applicable to other kinds of electro-magneticinduction-machinesas, for example, dynamoelectric machines or motors.

What I claim as new, and desire to secure by Letters Patent, is

1. The combination, with a circuit supplying direct current, of a rotarytransformer having an armature with a winding connected. throughcommutating devices to such circuit and a secondary winding connected toindependent commutating devices, and additional commutating devicesrotatable relatively tothe aforesaid comm utating devices and connectedwith a separate circuit and with the secondary winding, and means forrotating said additional commutating devices.

2. The combination, with a circuit supplying direct current, of a rotarytransformer having a field-magnet and a rotary armature with twoinsulated windings, a commutator connecting one of such windings to thesupply-circuit, and a commutator connected to the other winding andhaving two sets of collecting devices, one of which is fixed, while theother is rotatable relatively to said commutator.

3. The combination, with a circuit supplying direct current, of a rotarytransformer having a field-magnet and a rotary armature carrying twoseparate windings, each having a commutator, one of which connects itswinding with the supply-circuit, two sets of collecting devices bearingon the other commutator, one set being fixed and the other rotatable,and means for driving said rotatable collecting devices, substantiallyas described.

4:; The combination, with a circuit supplying direct current, of arotary transformer having a field-magnet and a rotary armature with twoinsulated windings, a commutator connecting one of such windings to thesupply-circuit, and a commutator connected to the other winding andhaving two sets of collecting devices, one of which is fixed, while theother is rotatable and is mechanically connected to the rotatingarmature through speed-reducing mechanism.

5. An electro-magnetic induction-machine havinga fixed fieldmagnetmounted on a central shaft, an exterior rotary armature surrounding saidfield-magnet and carrying two windings, sleeves surrounding said shaft,but supported out of contact therewith, and carrying said armature, acommutator for each Winding, and two sets of current-collecting devicesbearing on one of said commutators, substantially as set forth.

6. An electro-magnetic induction-machine comprising a fixed field-magnetand a rotating armature having interior radial progections clearing thefield-magnet by only asmall air-space and having two sets of coilssuperposed in the spaces between the projections, substantially asdescribed.

7'. The combination, with the rotary armature of an electromagneticinduction-machine, of a commutator connected to the winding thereof andtwo sets of collecting devices bearing on said commutator, one of whichis rotatable relatively to the other, each set being connected with anindependent circuit.

' 8. The combination, with the rotary armature of an electro-magneticinduction-machine, of acommutator connected to the winding thereof andtwo sets of collecting devices bearing on said commutator, one of whichis rotatable relatively to the other, each set being connected with anindependent circuit, and means for driving such rotatable collectingdevices.

9. The combination, with the rotary armature of an electromagneticinduction-machine, of a commutator connected to the winding thereof andtwo sets of collecting devices bearing on said commutator, one of whichis rotatable relatively to the other and is connected to the armaturethrough speed-reduction mechanism, each set being connected With anindependent circuit.

10. A current-collecting apparatus com prising a rotary commutatormounted on a shaft and current-collecting devices bearing on saidcommutator and supported on a ring surrounding said shaft and fixedwheels engagingwith said shaft and ring to support the latter and driveit at a reduced speed.

11. A rotary transformer comprising an interior cylindrical field-magnethaving its windin gin two diametrically-opposite notches, and aring-armature surrounding such fieldmagnet and having interiorlyprojecting teeth extending close to the periphery of the field-magnet,and primary and secondary coils wound around the armature and in eachspace between such teeth and commutating devices for suchcoils.

In witness whereof I have hereunto set my hand this 25th day of August,1891..

ELIHU THOMSON.

Witnesses:

JOHN W. GIBBoNEY, BENJAMIN B. HULL.

